Method of making mattresses, cushions, upholstery, heat and sound insulating coverings and the like



Filed Feb. 2,' 1956 March 17, 1959 K. H. HACKLNDER 2,878,153

METHOD oF MAKING NATTREssEs, cusHIoNs, UPHOLSTERY, HEAT AND souND INSULATTNG covERTNGs AND THE LINE V2 Sheets-Sheet 1 .4 Wliviiim l 2X @MyWay/Elia March 17, 1959 K. cKLANDl-:R 2,878,153

METHOD oF MAKING MATTRE cusHToNs, UPHOLSTERY, HEAT AND SOUND INSULATI-NG COVERINGS AND THE LIKE v 2 Sheens-Shee'l 2 Filed Feb. 2, 1956 United States Patent METHOD OF MAKING MATTRESSES, 'CUSHIONS, UPHOLSTERY, HEAT AND SOUND INSULATING COVERINGS AND THE LIKE Karl Hermann Hacklnder, Vaduz, Liechtenstein, assignor to Agricola Reg. Trust, Vaduz, Liechtenstein Application February 2, 1956, Serial No. 589,352

Claims priority, application Great Britain February 3, 1955` 8 Claims. (Cl. 154-106) This invention relates to mattresses, cushions, upholstery, heat and sound insulating coverings and the like.

The invention is concerned with the use of the resilient heat and sound insulating and absorbing properties of that class of exible plastics which is resilient due to the presence throughout the material of pores, generally known as resilient expanded plastic. One example of such a material is expanded polyurethane, sold under the name Moltopren Such material may be made in a variety of textures, from highly porous and very springy to very soft and having little porosity, as well as in the form of flakes, granules, chips and shreds which may be used for the filling of upholstery.

It is well known touse a thick sheet of a resilient expanded plastic as a mattress, for example, but full beneiit of the properties is not obtained as the material spreads, and, as it were, iiows away from under the load. Similarly, in the case of a seat cushion, the material in the thickness of the cushion moves radially, and in order to adequately support the weight a greater thickness of material is required than would be the case if such radial movement did not take place. Clearly such ow of the material will not take place in the case Where the area of the load i The invention consists in -a mattress, cushion, up-

holstery and such like constructed in part at least of resilient expanded plastic characterised in that in the absence of a load, the material adjacent the intended areaof contact with the load is under tension in a direction transversely of the direction of the load, while material remote from said area is under compression in a direction transversely ot' the direction of the load.

The accompanying drawings show, by Way of example only, a number of embodiments of the invention the characteristics of which will be apparent from the following description.

In the simplest form of construction comprising a circular cushionfor use on the seat of Ia chair, and constructed in accordance with the invention, is obtained when as shown in section in Figure l and plan in Figure la a single sheet 1 of the resilient expanded plastic is used say of '3 or 4 inches in thickness, the material is laid upon a flat table 2 and compressed by means of a circular shaped member 3 laid thereon approximately the size of the cushion required and when the material has been compressed say to 1A inch in thickness it is welded around the edge of the upper member by means of a shapedy heated tool or a wheel or other known method so that the pores are removed entirely along this line and upon removing of the upper member the sheet of material returns ap 2,878,153 Patented Mar. 17, 195,9v

from the outside of the weld as shown in Figure 3. It will be understood that in the action of returning to its original thickness the material towards the outer surfaces of the cushion becomes under tension while the material along the plane of the centre of the cushion becomes com pressed so that when a load is placed upon the cushion the action is to prevent the material from ilowing radially away from under the load.

In another form of construction as shown in Figure 4 of a similar cushion three layers of sheet vmaterial are placed one upon the other before being compressed and welded, the materials 4 on the outer surfaces of the sandwich being particularly chosen to resist stretching under the tension produced, while the material S in the centre of the sandwich is chosen to resist compression under stressing. The materials which are suitable in this case may also be suitable for lthe other purposes they serve, for example, theouter members 4 of the sandwich shown in Figure 5 may have a closer texture and form a suitable surface to prevent wear and slipping, while the inner sandwich 6 may consists of loose granules, flakes, chips and such like or reconstituted sheets of akes or scrap materials which are bound together, e. g. by adhesives or by the application of a moderate heat, that is, insuflicient to melt the material.

In a ystill further alternative form of construction of this simple form of cushion as shown in Figure 6 the outer layers 4 of the sandwich may be formedof resilient expanded plastic while the inner layer 7 of the sandwich maybe of rubberised hair or other well known suitable resilient uphostering 'materialwhich will withstand the compressing forces exerted by the stretching of the outer layers during the compression of the cushion.

In the last form of construction clearly the cushion cannot be compressed to the same degree when the central layer of the sandwich is not particularlyresilient as` is the case with the expanded plastic, and it may be necessary to apply stretching forces as` shown by the arrows 'to the outer layers while the cushion is being compressed in order to ensure that adequate tensional forces remain in the outer layers after the welding process has been completed. v

Where, however, for example, a highly porous plastic filling 'is' required for the sandwich, as when used say in a cinema seat, the said material may be provided with a number o f perforations extending through the in ner layer' 8 as shown in Figure 7 which are closed at Atheir ends either by the outer layers of the sandwich orby the seat structure and which thus form closed voids in thearticle. Such a construction will give considerable resilifence where the `load is light while the resilience will progressively decrease with increase of the load.4

` employed, it is also within the scope of the invention to attach the layers of the sandwich to one another around the periphery of the cushion as 'shown in Figure 9 by nl eans of sewing, by clips, staples or by any other suitable means `as desired.

To summarise therefore the simple form of construction so far described, the cushion may consist of a single layer of resilient ,expanded plastic having imparted to it during the manufacturing process tensionalforces at `and near'the surfaces and compressional forcesaroundvthe mid plane, the surfaces being brought into closev juxtaposition by welding; sewing or other means of fixing around the periphery so that said forces are produced and exist in the cushion until such time as a load is applied to the same. The nature of the cushion may vary through its cross section for example by forming a sandwich so that the material adjacent the surfaces is chosen to resist tensional forces while the material between is chosen to resist compressional forces.

It will be understood that the extent and the disposition of forces throughout the cushion depend on the relationship between the diameter of the cushion and the overall thickness of the same and that should the cushion be thin ascompared with its diameter forces will be only relatively slight at the centre and it is therefore proposed in accordance with the invention to weld the material through its thickness and between the surfaces at, for example, a point in the centre of a circular cushion as shown in Figure 10 thereby producing a 'further anchorpoint 9 from which the tensional and compressional forces may radiate. This anchor-point may be produced by the method first referred to, namely compressing the material between parallel plates and welding through a hole 10 provided in the centre of the circular top plate 11.

It is within the scope of the invention to so design the compression plate above referred to such that portions of the plate are raised in relation to the remainder as shown in Figure 1l and form heating electrodesby which the welding is carried out upon the surface of a table 2 below or upon electrodes 12 formed on a further plate 13 below asshown in Figure l2 so that a symmetrical arrangement is obtained.

Furthermore, a pattern may be embossed upon the surface lof the cushion or the like by projections upon the compressing plate or a further plate provided for this purpose as shown in Figure 13.

When a structure such as a mattress is required where thedimensions across the sheet of material are much lgreater than the thickness thereof many anchor-points 9 may be provided throughout the surfaces as shown in Figure 14 so that adequate stresses are incorporated in the structure and the tendency for the material to flow under the load imposed thereon is adequately resisted. These anchor-points may be formed 'at regular or irregular distances apart from one another so as to produce an interesting pattern upon the mattress.

In a still further alternative form of construction, besides the mattress being welded laround its edges by straight or curved lines, anchorage may be provided within the area of the surfaces by straight or curved lines either in addition to the anchor-points or alternative thereto, for example to form straight ribs from side to side or from end to end of the mattress as in a quilt or in a lattice pattern as shown in Figures 14 and 15.

The mattress, cushion, upholstery and the like may be constructed of a single sheet-like layer or three sheetlike layers to form a sandwich as above referred to, or an odd number of layers where the structure is required to be handled independently of any rigid structure to which it may be temporarily or permanently attached, whereby the forces within the material are symmetrical about a mid-plane, but where the structure is to be fixed to a rigid backing, for example the back or seat of a chair, an even number of layers may be provided, for example two, in which the outer layer retains the tensional stresses while the inner layer retains the compressional stresses, the upholstery being prevented from rolling up by direct or indirect attachment to the rigid backing.

Alternatively, as Shown in Figure 16, the structure may be constructed of a single thin layer of material which normally would be symmetrical after welding and there fore have tensional stresses at and near the surfaces and compressional stresses between and then be attached around its edge to a at rigid surface 14 such as plywood in which the action of attachment will increase the tensional stresses at the outer surface as shown by the arrows and transfer the compressional stresses from the middle of the structure to the surface adjacent the backing. Such treatment of the structure then converts the upholstery from a symmetrical arrangement to a nonsymmetrical arrangement. Such a structure also is within the scope of the invention. f

In order that there shall be adequate material for atl tachment to a backing either in the above or any other formvof construction the weld may be made that much wider and so produce a ange around the article as shown' in Figure 17 or two separate welds may be made the one adjacent the other for the same purpose.

Seeing that when a mattress or cushion is constructed in accordance with one method of carrying the invention into effect by the application of pressure between parallel surfaces while the welding process is being carried out and tensional and compressional forces are not existent at this time, it can be clearly understood that when a load is applied to such a mattress or cushion which covers substantially the whole of the surface during use the tension and compression forces are relieved, and the resilience of the material supports the load wholly normally to the surfaces thereof and transverse flow of the mate` rial is eliminated.

Where for any reason it is inconvenient tovprovide a press large enough to accommodate a mattress or any substantial rarea of material which it is required to make up in accordance with the invention, a sandwich may be formed and the outer surfaces of material be attached to means for stretching it in its own plane as shown by the arrows in Figure 18 without compressing between parallel surfaces and before the Welding or sewing is carried out around the periphery. The welding may be then effected by means of a smaller heated hand wheel which may be caused to follow a curved path to a particular design and at the samer time or subsequently anchor-points or anchor-lines may be introduced independently by hand as and where required to join the front and back surfaces together. It can therefore be seen that the invention is not limited to the method of compression between parallel surfaces although this method is found to be most effective as the work can be carried out more rapidly by this means.

Where it is required for the finished product to have a corrugated or waved or other shape imparted to it as shown in Fig. 19, the surfaces between which the sandwich or single layer is compressed may be curved or shaped and consequently the method of compression during the welding process is not limited to flat parallel plates. For example, where a mattress is required for heat insulating or sound insulating or absorbing purposes and is required to cover a semispherical surface the compressing surfaces may be suitably shaped so that the finished product is of the desired curvature.

The method and product in accordance with the, invention is particularly applicable to use with upholstery covering large surfaces such as aeroplane seats, divans, and the like, while the curved or cylindrical parts required may be formed during the forming of the main load carrying surfaces of the seat and back as shown in Figure 20, the whole structure being attached to a at backing either along the lines of the welds or by adhesive with the whole of the back.

Sheets of material formed in accordance with the invention are particularly useful for lining walls, ceilings, etc. for heat insulating and sound insulating and absorbing purposes and can be constructed by a continuous process in'which pressure is applied to the single sheet or the sandwich of material by a roller or a system of. rollers 17 and 18 as shown in Figure 21 while the welds are applied simultaneously in a similar manner by theelectrodes 12. Such a material may bacon-L.

asvsn'ss veniently attached to the backing along the lines of the welds.

Where desired, a decorative or wear-resisting fabric 15 may be placed on the surface of the single sheet or sandwich as shown in Figure 22 during the forming process and, if of a thermoplastic nature, becomes attached to the final mattress, cushion or upholstery along the lines of the welds 16 and becomes incorporated in the iinal product, and due to the compressing .process is held stretched between the welds by the resilient action of the layer or layers when released from the pressure.

Where the mattress, cushion, upholstery or the like is used for the purpose of supporting the human body it is preferable that the material be of the kind in which the vpores are interconnected so that the material may breathe and condensation be prevented from forming, but when such use is not made of thestructures the material in which the pores are not interconnected can also be used satisfactorily. y

Small cushions or pads constructed in accordance with the invention may be employed as cleaning pads for motor vehicles andthe like in which a hose is ,fixed into a recess in the material and is welded closely around the same, so that water issuing from the hose emerges by way of the pores in the material over the surface of the pad. Also an earphone or a small loud-speaker may be inserted in a cushion before it is welded, such a cushion being of particular use in hospitals and such institutions.

In a still further construction in accordance with the invention, fabric membranes,.e. g. a net extensible in all directions,v may be incorporated in the sandwich to resist the overall stretching of the-mattress or upholstery, particularly in such situations where the structure is attached around its edges and is not provided with an overall backing and other variations in the forming of the structurre may be carried out without departing from the scope of the invention.

I claim:

l. A method of forming resilient upholstery consisting at least in part of thermoplastic organic plastic expanded by having pores therein and having two opposite faces, comprising the steps of compressing resilient expanded plastic over at least a substantial part of the area of the upholstery to close up the pores therein and reduce the thickness, applying heat over relatively small portions of the compressed area to render them plastic and remove the pores therefrom, allowing the heated portions to cool and solidify and releasing the compression to allow the pores of the main body of the upholstery to open and the main body to return to substantially its original thickness, whereby the plastic adjacent at least one of the opposite faces of the upholstery is stressed by being under tension in a direction parallel with said face or faces while the plastic remote from said face or faces is stressed by being compressed parallel with said face or faces.

2. A method of forming resilient upholstery consisting at least in part of thermoplastic organic plastic expanded by having pores therein and having edge portions of unexpanded plastic and two opposite faces, comprising the steps of compressing resilient expanded plastic over at least a substantial p-art of the area of the upholstery to close up the pores therein and reduce the thickness, applying heat over relatively small portions of the compressed area including at least those portions of the plastic which will form the edge portions of the upholstery to render them plastic and remove the pores therefrom, allowing the heated portions to cool and solidify land releasing the compression to allow the pores of the main body of the upholstery to open and the main body to return to substantially its original thickness, whereby the plastic adjacent at least one of the opposite faces of the upholstery is stressed by being under 6 tension in a direction parallel with said face or vfaces" while the plastic remote from said face or faces is stressed by being compressed parallel with said face or faces.

3. A method of forming resilient upholstery consisting at least in part of thermoplastic organic plastic expanded by having pores therein and having Yedge portions of unexpanded plastic and two opposite faces, cornprising the steps of compressing resilient expanded plastic over at least a substantial part of the area of 4 the upholstery to close up the pores therein and reduce the thickness, applying heat over relatively small portions of the compressed area including at least those lportions of the plastic which will form the edge portions of the upholstery to render them plastic and remove the pores therefrom, allowing the heated portions to cool land solidify, releasing the compression to allow the pores of the main body of the upholstery to open land the main body to return .to substantially its original thickness, whereby the plastic adjacent at least one of the opposite faces of the upholstery is stressed by being under tension in a direction parallel with said face or faces while the plastic remote from said face or faces is stressed by being compressed parallel with said face or faces, and trimming away surplus plastic from outside the boundary dened by said edge portions.

4. A method of forming resilient upholsteryconsisting at least in part of thermoplastic organic plastic expanded by having pores therein and having edge ,portions of unexpanded plastic and two opposite faces, cornprising the steps of compressing resilient expanded plastic over at least a substantial part of the. area of theupholstery to close up the pores therein and reduce the thickness, applying heat over relatively small portions of the compressed area comprising those portions of the plastic which will form the edge portions of the upholstery and anchor points within the main body of the upholstery to render them plastic and remove the pores therefrom, allowing the heated portions to cool and solidify and releasing the compression to allow the pores of the main body of the upholstery to open and the main body to return to substantially its original thickness, whereby the plastic adjacent at least one of the opposite faces of the upholstery is stressed by being under tension in a direction parallel with said face or faces while the plastic remote from said face or faces is stressed by being compressed parallel with said face or faces.

5. A method of forming resilient upholstery consisting at least in part of thermoplastic organic plastic expanded by having pores therein and having edge portions of unexpanded plastic and two opposite faces, comprising the steps of compressing resilient expanded plastic over at least a substantial part of the area of the upholstery to close up the pores therein and reduce the thickness, applying heat over relatively small portions of the compressed area comprising those portions of the plastic which will form the edge portions of the upholstery and anchor lines within the main body of the upholstery to render them plastic and remove the pores therefrom, allowing the heated portions to cool and solidify and releasing the compression to allow the pores of the main body of the upholstery to open and the main body to return to substantially its original thickness, whereby the plastic adjacent at least one of the opposite faces of the upholstery is stressed by being under tension in a direction parallel with said face or faces while the plastic remote from said face or faces is stressed by being compressed parallel with said face or faces.

6. A method of forming resilient upholstery consisting in part of thermoplastic organic plastic expanded by having pores therein and having two opposite faces, comprising the steps of compressing resilient expanded plastic in the form of a mass of shreds and granules of plastic sandwiched between two or more sheets of plastic forming the said faces, over at least a substantial part of the area of the upholstery to close up the pores theref in and reduce the thickness, applying heat over relatively Vsmall portions of vthe compressed area to render them plastic and remove the pores therefrom, allowing the heated portions to cool and solidify and releasingthe compression to allow the pores of the main body of the upholstery to open and the main body` to return to sub-l stantially` its original thickness, whereby the plastic adjacentat least one of the opposite faces of the upholstery is stressed by being under tension in a direction parallel withsaid` face or faces while the plastic remote from said face or `faces is stressedby being compressed paral lelwith said face or faces.

1'l'. A method of forming resilient upholstery consisting at least in part of thermoplastic organic plastic expanded by having pores therein and having'two opposite faces,`comprising the steps of compressing expanded plastic in the form of two outer sheets of expanded plastic having one degree of resilience and a sheet of expanded plastic having a different resilience sandwiched therebetween over at least a substantial part of the area of the upholstery to close up the pores therein and reduce the thickness, applying heat over relatively small portions of the compressed area to render them plastic and remove the pores therefrom, allowing the heated portions to:cool and vsolidify and releasing the compression to allow-the pores of the main body of the upholstery to open and the main body to return to substantially its original thickness, whereby the plastic adjacent at least oneof the opposite faces of the upholstery is stressed by being under ltension in a direction parallel with said face or faces while the plastic remote from said face or faces is stressed `by being compressed parallel with said face or faces.

8. A- method of forming resilient upholstery consist-` ing at least in part of polyurethene expanded by having pores therein and having two opposite faces, comprising the steps of compressing expanded polyurethene over at least a substantial part of the area of the upholstery to close up the pores therein and reduce the thickness, applying heat over relatively small portions of the com pressed area to render them plastic and remove the pores therefrom, allowing the heated portions to cool and solidify and releasing the compression to allow the pores of the main body of the upholstery to open and the main body to return to substantially its original thickness, whereby the polyurethene adjacent at least one of the opposite faces of the upholstery is stressed by being under Atensionv in a direction parallel with said face or faces while the polyurethene remote from said face or faces is stressed by being compressed parallel with said face or faces.

References Cited in the file of this patent UNITED STATES PATENTS 1,345,046 Wedlock June 29, 1920 2,071,647 Miller Feb. 23, 1937 2,201,669 Kraft May 21, 1940 2,371,954 Cunningham Mar. 20, 1945 2,425,388 Oestricher Aug. 12, 1947l 2,434,527 Untiedt Jan. 13, 1948 2,495,045 Woodbury et al. Jan. 17, ()A 2,521,984 Lang Sept. l2, 1950 2,552,476 Barton May 8, 1951 2,603,391 Kaufman July 15, 1952 2,702,769 Alderfer Feb. 22, 1955 2,767,436 Noland et al. Oct, 23, 

1. A METHOD OF FORMING RESILIENT UPHOLSTERY CONSISTING AT LEAST IN PART OF THERMOPLASTIC ORGANIC PLASTIC EXPANDED BY HAVING PORES THEREIN AND HAVING TWO OPPOSITE FACES, COMPRISING THE STEPS OF COMPRESSING RESILIENT EXPANDED PLASTIC OVER AT LEAST A SUBSTANTIAL PART OF THE AREA OF THE UPHOLSTERY TO CLOSE UP THE PORES THEREIN AND REDUCE THE THICKNESS, APPLYING HEAT OVER RELATIVELY SMALL PORTIONS OF THE COMPRESSED AREA TO RENDER THEM PLASTIC AND REMOVE THE PORES THEREFROM, ALLOWING THE HEATED PORTIONS TO COOL AND SOLIDIFY AND RELEASING THE COMPRESSION TO ALLOW THE PORES OF THE MAIN BODY OF THE UPHOLSTERY TO OPEN AND THE MAIN BODY TO RETURN TO SUBSTANTIALLY ITS ORIGINAL THICKNESS, WHEREBY THE PLASTIC ADJACENT AT LEAST ONE OF THE OPPOSITE FACES OF THE UPHOLSTERY IS STRESSED BY BEING UNDER TENSION IN A DIRECTION PARALLEL WITH SAID FACE OR FACES WHILE THE PLASTIC REMOTE FROM SAID FACE OR FACES IS STRESSED BY BEING COMPRESSED PARALLEL WITH SAID FACE OR FACES. 